The air-fuel ratio in a combustion engine affects both engine emissions and performance. With strict modern emissions standards for automobiles, it is necessary to control accurately the air-fuel ratio of the automobile engine, requiring precise measurement of the mass airflow into the engine.
Currently, engine airflow is either measured with a mass airflow sensor or calculated by the speed-density method. In general, while mass airflow sensors are more accurate than speed-density systems, they are also more expensive.
What is desired is an airflow measurement system that eliminates the expensive airflow sensors of current fast response systems while offering the same improved air-fuel ratio control, easy calibration and adaptability to changing conditions.